The rear fender lost its front stay a while back, the little wire strut that holds the front lip off the tire. So now it hangs from the one bolt at the seat stays, and it swings from that bolt like a door with one hinge.
There is a speed where it rattles. Around fifteen, on smooth road, the fender finds its note and starts to buzz against nothing, a steel shiver you feel in the frame more than hear. Below that speed, silence. Above it, silence. Just that one band, a hornet trapped in the middle of the gears, and I ride through it either slower or faster on purpose, splitting the difference around a defect I could just fix.
The bumps are worse. On a bump the loose front lip drops and kisses the tire, and the tire says so, a wet slapping drag that scrubs a little speed and leaves a black arc of rubber dust on the underside of the steel. On a wet day it throws that back at my heel. I have a gray stripe up the back of one pant leg that the wash does not entirely take.
The bolt itself is fine. That is the joke. The one fastener still doing its job is doing it perfectly, holding the whole flapping mess to the bike, faithful to a fender that has otherwise resigned.
I bent the front lip up with my thumb before I rode today, away from the tire, to buy quiet. By the corner it had sagged back down. I heard it find the rubber again just as I stopped pedaling, one soft touch, and then the coast carried me the rest of the way in without another sound.